Thermostatic apparatus



Feb. 24, 1931. J. w. MYERS 1,793,954

THERMOSTATIC APPARATUS Filed May 16, 1927 1X1 'EN TOR. W W- A TTORXEPatented Feb. 24, 1931 UNITED STATES JOSEPH W. MYERS, bl JACKSON,MICHIGAN rnnamos'ra'rro ArrARArus Application filed May 16, 1927. SerialNo. 191,621.

My invention relates to a thermostatic apparatus, and an object of myimprovements is to provide'a simple and easily adjusted apparatus thatis inexpensive to manufacture a that shall positively, certainly andeffectively make a circuit at one prescribed temperature and break it atanother prescribed temperature. I secure this object in the deviceillustrated in the accompanying drawing, in

which:

Figure 1 is a longitudinal sectional view of an apparatus embodying myinvention.

Figure 2 is a side elevation of the right hand portion of the same.

Figure 3 is an elevation, looking from the right of Figure 1, with partsremoved to show the interior construction. I Figure 4 is a sectionalplan view of the construction of Figure 3.

Figure 5 is a perspective view of a part of the device detached,illustrating a modified construction. v

Figure 6 is a diagram illustrating a modie fication of the construction.

2 is a cylindrical casing. 3 is a rod located within the casing 2coaxial therewith and adapted to be-rotated therein. The rod 3' extendsthrough the right hand end of the casing 2 in a joint permitting it tofreely rotate. 4 is a bimetallic strip wound in the form of a spiralsurrounding'the rod 3 attached to the casing 2 at its left hand end andto the rod 3 at 43 at its right hand end. The strip 4. will'be actedupon by a change of temperature to rotate the rod 3.

- 5 is a plate secured to the right hand end of the casing 2 and havingits periphery turned to form a coaxial flange 52, making of the plate'5with its upturned flange a cup like construction opening away from thecasing 2. 7 isacylinder closed at its right hand end and having its openleft hand end fitted and beaded into the flange 52 so as to be rotatabletherein, but held from axial motion relative thereto. 8 is a metal band,having a scale on its outer surface fitting around the I periphery ofthe cylinder 7. 6 is a pointer secured to the plate 5 and having its endextending over the scale band 8. 9 is a plate riveted to the cylinder 7coaxial therewith at its center and bending away from said cylinder andaround the edge thereof. The plate 9 serves for a handle for rotatingthe cylinder 7, which will keep cooler than said cylinder and present aconvenient periphery to be grasped by the hand. 11 is a conicaltorsional spring, one end of which is secured to the cylinder 7 and theother end to the right hand end of therod 3. Thus by setting thecylinder 7 at diiferent angular positions corresponding torsional forcesare applied through said 1 spring to the rod 3.

12 is a base plate secured to the right haiid end of'the rod 3. 13 is anarm of bimetalic metal extending from the plate 12 and having a contactpiece 15 at its outer end. 14 is a rigid guard plate secured to the baseplate 12 and adapted to limit the outward move ment of the arm 13. 16 isa stationary plate secured to the plate 5 and provided with insulatedbinding posts 17 and 18. 19 is a-contact plate extendin from the bindingpost 18 and adapted to e contacted by the plate 15. 20 is a flexibleconducting connection between the binding post 17 and the arm 13. Thebinding posts 17 and 18 are connected in the usual way in a circuit,which is made and broken by the contact and separating of the contacts15 and 19.

The operation of the above described device is as follows:

If weassume thatthe contacts 15 and 19 are separated and we wish them toclose at a certain temperature, the plate 9 is turned by the operatoruntil the pointer 6 indicates the selected temperature on the scale ofthe plate 8. When .the temperature has fallen sufficiently the spiral 41acts upon the rod 3 to twist the same against the reaction'of the spring11 and bring the contact 15 in contact with 19, thus completing thecircuit. The current passing through the arm 13 heats up said armto acertain extent which causes it to tend to bend inward pressing thecontact 15 harder against the contact 19. When the temperature rises,acting upon the strip 4 so as to tend to separate the contact plates 15and 19, the separation of said plates takes laceafter the extra ressure,due to the nding of the arm 13 y its increased temperature, has beenovercome. The contacts 15 and 19 are then positively separated and thecircuit is broken interrupting the current passing through the arm 13.Which is no longer heated thereby and therefore its temperature fallsbending the arm outward to its first position.

Instead of passin the current directly through the metal 0 the arm 13 itmay be passed through a coil of special metal 13a surrounding said armand acting to heat the same, as shown in Figure 5, and in either case ashort circuit 22 may be provided having a rheostat 21 therein, which maybe adjusted to regulate the amount of current passing through the arm 13with which it is in parallel circuit or through the coil 13a, as thecase may be, to regulate the amount of flexing of said arm bythecpassing currents What I claim is:

1. The combination of. an electric circuit,

- coacting contacts in said circuit, a thermostat adapted to actuatesaid contacts to make and break said circuit and a part adapted to beheated by the current in said circuit when said contacts are inengagement so as .to complete said circuitand adapted to be actuated bya changing of its temperature due to the current in said circuit, and toact to press said contacts together when heated by said current.

2. The combination of an electric circuit, coacting contacts in saidcircuit, a thermostat adapted to actuate said contacts to make and breaksaid circuit and a part adapted to be heated by the current in saidcircuit when said contacts are in engagement so as to comiplete saidcircuit and adapted to be actuate by a changin of. its temperature dueto the current in sai circuit, andto act to press said contacts togetherwhen heated by said current, and means for regulating the currentheating said part whereby the temperature at which separation of thecontactsoccur is determined. 1

3. The combination of an electric circuit, coacting contacts in saidcircuit, a thermostat, a bimetallic arm adapted to be flexed .by achange in its temperature due to the current in saidcircuit, saidthermostat being adapted to actuate said arm to bring said contactstogether, and separate the same, to make and break said circuit, a partof said circuit being adapted to heat said arm when a. said circuit iscomplete and said contacts are engaged and cause it to bend to press onecontact towards the other whereby the tempera required torsional stressto said spring.'

5. The combination of a rod 3, an arm carried by said rod, a thermostatadapted to rotate said rod, a stationary. contact, a cothe directionopposite to that of said therf mostat and means adapted to be set toapply operating contact carried by said arm, a;

casmg enclosing said rod and arm, a part of the wall of said casingcoaxial with said rod adapted to be set at various angular positions anda torsion spring secured to said rod and said part of the wall coaxialtherewith.

6. The combination of a rod 3, a cylindg,

ing and "forming an end thereof and a torsional spring engaging said rodand said partsubstantially as and for the purpose described;

In testimony whereof, I sign this specification.

- JOSEPH W. MYERS.

ature at which separation of the contacts occur is determined.

4. In combination with an electric circuit, a contact, a pivoted arm, athermostat" adapted to turn said arm about its pivot, a second contactcarried'by said arm adapted to cooperate with the first named contact, atorsion spring tendingto turn said arm in

